Thermally operated valve for automatically modulating the flow of fluids

ABSTRACT

A valve for automatically modulating a flow of fluid. The valve includes a flexible flow adjustment member having a variable diameter passage therethrough and an outer surface and a shell surrounding at least a portion of the outer surface and creating a void between the shell and the outer surface. The shell is in contact with the flow of fluid. The valve further includes a thermally reactive material that expands when heated and contracts when cooled. The thermally reactive material is within the void and is in contact with the outer surface of the flexible flow adjustment member. The thermally reactive material exerts pressure on the flexible flow adjustment member in response to a heating of the thermally reactive material to cause the variable diameter passage to close and to relieve pressure thereon in response to a cooling of the thermally reactive material to permit the variable diameter passage to open. The flow of condensate is permitted to pass through the variable diameter passage at an average temperature that generally parallels the average temperature of saturated steam within the steam system within a range of about 0 to 40 percent. The average maximum temperature of condensate flow permitted to pass through the variable diameter passage differs from the average minimum temperature of condensate flow permitted to pass through the variable diameter passage by up to about 25 degrees Fahrenheit.

BACKGROUND OF THE INVENTION

The present invention relates to thermally operated valves and, moreparticularly, to a thermally operated valve which automaticallymodulates the flow of fluids therethrough.

In the design, construction and operation of manufacturing, process andchemical plants, the control of fluid flow is a major concern to thedesign and operating engineer. It is also critical in environmentalheating and cooling systems. The size and type of valves utilized atvarious control points result in a major portion of the cost of designand construction. In many applications it is desired to automaticallycontrol the flow of the fluid through a pipe, wherein the opening orclosing action is effected directly by the temperature of the fluid flowbeing controlled. While one of the largest applications for this type ofvalve is the steam trap, there are many additional uses for valves ofthis type. For the purpose of clarification, the utility of the controlvalve of this invention will be described as it is applied to the steamtrap application, but the control valves of this invention are notlimited to that application.

In process or manufacturing plants, the steam trap provides an extremelyimportant function. When operating properly and efficiently, it reducesthe waste of energy and conserves heat energy in the system. However,when it is inoperable or performing inefficiently through corrosion,dirt, misuse, or simply through selection and installation of a valve ofthe wrong size or type, heat and energy losses are substantial. Steam,as it releases its heat units through process application, piperadiation loss, or by other means, ultimately returns to its water orcondensate state. If this condensate is not drained immediately ortrapped from the system, it reduces the operating efficiency by slowingthe heat transfer process and can actually cause physical damage to theequipment.

The condensate accumulates along the bottom of horizontal pipe and isswept along by the steam flow passing over it. Depending upon the volumeand velocity, condensate may collect and fill the pipe, continuing to beswept along by the steam flow. If the velocity is sufficient, this waterflow can do substantial damage to the equipment. It is thereforedesirable in essentially all steam operated systems to remove thecondensate as often and as efficiently as is practically possible. Thecondensate typically forms and collects at elevation changes such asrisers and expansion loops, at all low points and on long horizontalruns and, of course, ahead of all dead-end areas, such as shut offvalves, pressure and temperature control valves and at the ends of steammains. In particular it is important to remove condensate ahead ofhumidifiers, pumps, turbines and other equipment where water dropletsmay damage the equipment. In order to improve efficiency, steam trapsare used downstream from heat exchangers, coils, unit heaters, cookingkettles, dryers, and the like. The temperature at which the condensateis discharged may be quite important to maintaining energy efficiency.

With all these various uses and positions for steam traps in the processsystem, and because of the physical and performance limitations on thevarious types of steam traps, many different types have been designedand marketed. While all of the many different types of steam trapsoperate by sensing the difference between steam and condensate, they maybe classified as density operated (mechanical), temperature operated(thermostatic) and kinetic energy operated (disc and orifice). All ofthese various types have been necessary because of the limitations ofthe performance of the traps and not necessarily due to the result ofthe specific operating principle involved. Thus, although the device ofthis invention is temperature operated, it does not necessarily fallinto the same category or have the limitations of the temperatureoperated steam traps presently available which include thebalance-pressure thermostatic traps and the thermostatic traps which arecharacterized as liquid-expansion and bi-metal expansion traps. Theoperation, advantages, and limitations of these various types of trapsare well known to process engineers and are described in Bulletin NumberT-511 printed April, 1979 by Sarco Company, 1951 26th Street, S.E., PostOffice Box 119, Allentown, Pa. 18105, entitled “Steam Trap Selection andApplication Guide,” incorporated herein by reference. As will be clearfrom this “Guide,” the choice of the particular kind of trap isimportant for the application and needs of the particular situation.

The “choice” problem relates not only to the type of trap, but also tothe size of the trap, thereby requiring a thorough study of the rate ofthe expected flow and the characteristics of that flow before choosingthe particular type and size of trap. These traps are expensive,complicated, and their selection involves a substantial portion of thetotal planning time in construction of a system. An incorrect choice oftype or even size can result in poor performance or even complete lackof performance and could potentially damage equipment. Because of thenature of the device, it is common to use larger steam traps thannecessary as they provide a substantial safety. factor, and if the steamtrap is found to be too small for the particular location, substantialexpense and delay may be required before the system becomes operational.However, a trap having a capacity which is greater than systemrequirements may be energy inefficient and is certainly more costly. Inaddition, redundant systems are required because steam traps createnotorious maintenance problems and are likely to need regular servicing.Strainer plugging is a common problem. As the steam trap ages,inefficiencies set in due to wear and due to deposition of varioussolids at the critical moving parts. It is common to fix or replace thesteam traps in an entire system at regular intervals.

A particular problem with essentially all of the prior steam traps isdetermining how well the device is performing. In many applications, asubstantial steam leak which results in energy losses cannot be easilydetected. Such techniques as ultrasonic detection and other diagnostictools are necessary to study the trap operation while “on stream.” Manyof the more costly and more efficient steam trap devices, however, areaffected by particulates such as dirt or scale that might clog theworking mechanism of the trap. This requires filtration upstream throughthe use of strainers and other such devices.

With the importance of energy conservation, particularly in processplant and boiler operations, even on a small scale, the steam trap andits efficient performance is a major concern. However, nothing has beenoffered as a satisfactory solution of various limitations of thepresently available steam traps. These limitations include low thermalefficiency under varying loads and pressures, allowing steam loss duringoperation, the necessity of maintaining a water seal to avoid continuousdischarge of steam, protection from freezing, limited discharge ofcondensate on a continuous basis, limited air venting capacity,inability to adjust the trap on-stream limited use with super heatedsteam, on-stream damage due to water hammer, closure of the trap due tofailure, protection from any steam impingement that might damage theequipment, failure to be self-adjusting to various pressure changes ofthe steam flow, requiring an open discharge outlet at the site of use,inconsistent operation particularly upon aging, being limited to lowpressure operation, the design or construction requiring continuoussteam bleed resulting in substantial waste even with light loads, use ofmechanical parts which are subject to sticking, water logging of theflow system because of condensate holdback, and being limited to certaininlet pressures. These limitations are not present in all types of steamtraps, but each type of steam trap suffers with some of theselimitations and even the best choice leaves some disadvantages.

None of the prior art devices have provided a solution to thelimitations of the steam traps and control valves as outlined above.Accordingly, it is an object of this invention to provide a controlvalve that operates on the principle of temperature increase in a fluidstream to control the rate of flow of that fluid. The present inventionprovides a steam trap that does not use a mechanical float orthermo-expansion of a bellows to close or open a machined orifice with atapered plug. Accordingly, this invention provides a steam trap designthat is not prone to wear, plugging, or substantial maintenance problemsrelating to internal components of typical steam traps. Furthermore, thepresent invention provides a trap that is not affected by or subject tofreezing, due to the requirement of a condensate reservoir or theinternal design of the device. The present invention also vents allsystem air, accumulated water and non-condensables as soon as possibleand provides a cold port opening through the steam trap. The presentinvention also provides a flow path adequate to pass particulates andfluid surges without clogging or restriction of flow.

The present invention is multipurpose in nature, such that it may beused with a wide range of condensate flow rates, operating pressures,pipe sizes and system applications. Further, the present inventionprovides a trap with essentially no metal wear parts, and which iscapable of insertion in-line and is compact in size by comparison withpresent steam traps. It is not limited to use as a stream trap, but canbe used in any setting where a fluid flow must be modulated orcontrolled in response to an input temperature.

The present invention also operates such that cooler temperatures expandthe orifice and increase flow through the trap to provide a quick andcomplete discharge of condensate liquid, particularly on start-upconditions. Unlike prior art devices, the present invention providesvery rapid response to direct steam contact with the trap and to changesin the temperature of the flow generally. Further, the valve of thepresent invention provides a closure valve that will compensate forerosion of the inside surface to prevent leakage. For increased safetyover prior art designs, the valve of the present invention will notremain in the closed position in the event of a failure, but will returnto the open position. For increased economic efficiency, the valve ofthe present invention has a long performance life and will be lessexpensive to install and operate.

It will be understood that the valve of the present invention is notlimited to application as a steam trap in a steam system but may be usedin any setting where a fluid flow must be modulated or controlled inresponse to an input temperature.

BRIEF SUMMARY OF THE INVENTION

A valve for automatically modulating a flow of fluid. The valve includesa flexible flow adjustment member having a variable diameter passagetherethrough and an outer surface and a shell surrounding at least aportion of the outer surface and creating a void between the shell andthe outer surface. The shell is in contact with the flow of fluid. Thevalve further includes a thermally reactive material that expands whenheated and contracts when cooled. The thermally reactive material iswithin the void and is in contact with the outer surface of the flexibleflow adjustment member. The thermally reactive material exerts pressureon the flexible flow adjustment member in response to a heating of thethermally reactive material to cause the variable diameter passage toclose and to relieve pressure thereon in response to a cooling of thethermally reactive material to permit the variable diameter passage toopen. A substantial portion of the thermally reactive material isconfigured to change phase to vapor in response to an increase intemperature within the internal cavity.

In another aspect, the present invention is directed to a valve forautomatically modulating a flow of fluid. The valve includes a flexibleflow adjustment member having a variable diameter passage therethroughand an outer surface. The valve also includes a shell surrounding atleast a portion of the outer surface and creating a void between theshell and the outer surface. The shell is in contact with the flow offluid. A thermally reactive material that expands when heated andcontracts when cooled, the thermally reactive material is within thevoid and in contact with the outer surface of the flexible flowadjustment member. The thermally reactive material exerts pressure onthe flexible flow adjustment member in response to a heating of thethermally reactive material to cause the variable diameter passage toclose and to relieve pressure thereon in response to a cooling of thethermally reactive material to permit the variable diameter passage toopen. The thermally reactive material includes about twenty to fiftypercent glycerin by volume, about zero to twenty percent water byvolume, and about fifty to sixty percent alcohol by volume.

In another aspect, the present invention is directed to a valve forautomatically modulating a flow of condensate from a steam system thatincludes steam at a saturation temperature. The valve includes aflexible flow adjustment member having a variable diameter passagetherethrough and an outer surface. The valve also includes a shellsurrounding at least a portion of the outer surface and creating a voidbetween the shell and the outer surface. The shell is in contact withthe flow of fluid. The valve also includes a thermally reactive materialthat expands when heated and contracts when cooled. The thermallyreactive material is within the void and in contact with the outersurface of the flexible flow adjustment member for exerting pressurethereon in response to a heating of the thermally reactive material tocause the variable diameter passage to close and to relieve pressurethereon in response to a cooling of the thermally reactive material topermit the variable diameter passage to open. The flow of condensate ispermitted to pass through the variable diameter passage at an averagetemperature that generally parallels the average temperature ofsaturated steam within the steam system within a range of about 0 to 40percent. The average maximum temperature of condensate flow permitted topass through the variable diameter passage differs from the averageminimum temperature of condensate flow permitted to pass through thevariable diameter passage by up to about 25 degrees Fahrenheit.

In another aspect, the present invention is directed to a valve forautomatically modulating a flow of condensate from a steam system. Thevalve includes a housing having a wall defining an interior cavity. Theinterior cavity is in fluid communication with the steam system. Amodulator is mounted within the interior cavity. The modulator includesa shell in fluid communication with the steam system and a flexible flowadjustment member within the shell. The flexible flow adjustment memberhas a variable diameter passage therethrough. The variable diameterpassage is in fluid communication with the steam system. The modulatorincludes a void between the flexible flow adjustment member and theshell and a thermally reactive material within the void. The thermallyreactive material is in contact with the shell for thermal communicationtherebetween. At least a portion of the thermally reactive material isconfigured to change phase to vapor in response to an increase intemperature within the internal cavity.

In another aspect, the present invention is directed to a valveincluding a housing having a wall defining an interior cavity. The valvealso includes a modulator mounted within the interior cavity. Themodulator includes a shell in fluid communication with the interiorcavity and a flexible flow adjustment member within the shell. Theflexible flow adjustment member has a variable diameter passagetherethrough. The variable diameter passage is in fluid communicationwith the interior cavity. The modulator also includes a void between theflexible flow adjustment member and the shell and a thermally reactivematerial within the void and in contact with the shell for thermalcommunication therebetween. At least a portion of the thermally reactivematerial is configured to change phase to vapor in response to anincrease in temperature within the interior cavity.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe preferred embodiment of the invention, will be better understoodwhen read in conjunction with the appended drawings. For the purpose ofillustrating the invention, there is shown in the drawings an embodimentwhich is presently preferred. It should be understood, however, that theinvention is not limited to the precise arrangements andinstrumentalities shown. In the drawings:

FIG. 1 is a cross-sectional view of a thermally operated valve inaccordance with a preferred embodiment of the present invention;

FIG. 2 is a top plan view of a modulator in accordance with thepreferred embodiment shown in FIG. 1, taken along line 2—2 of FIG. 1;

FIG. 3 is a partial cross-sectional view of the end washer, flexibleflow adjustment member and flanged nipple of the modulator shown in FIG.2 taken along line 3—3 of FIG. 2;

FIG. 4 is a complete cross-sectional view of the modulator for thethermally operated valve shown in FIG. 2 taken along line 3—3 of FIG. 2;

FIG. 5 is a cross-sectional view of a preferred embodiment of acompression tool used to assemble the modulator shown in FIG. 4;

FIG. 6 is a top plan view of a segmented cone assembly of thecompression tool shown in FIG. 5;

FIG. 7 is a cross-sectional view of the segmented cone assembly shown inFIG. 6 taken along line 7—7 of FIG. 6;

FIG. 8 is an elongated cross-sectional detail view of a receiver of thecompression tool shown in FIG. 5;

FIG. 9 is a cross-sectional view of an end plug of the compression toolshown in FIG. 5;

FIG. 10 is a cross-sectional detail view of a plunger and coil spring ofthe compression tool shown in FIG. 5; and

FIG. 11 is a cross-sectional detail view of a base plate and retainerplate of the compression tool shown in FIG. 5;

FIG. 12 is a block diagram showing a steam system test apparatus;

FIG. 13 is a graphical representation of a test of a prior artthermodynamic steam trap performed on the steam system test apparatusshown in FIG. 12;

FIG. 14 is a graphical representation of a test of a prior artbucket-type steam trap performed on the steam system test apparatusshown in FIG. 12; and

FIG. 15 is a graphical representation of a test of the valve of thepreferred embodiment as shown in FIG. 1, performed on the steam systemtest apparatus shown in FIG. 12.

DETAILED DESCRIPTION OF THE INVENTION

As used in the claims, “a” is defined as “at least one”. In thedrawings, like numerals are used to indicate like elements throughout.Referring to the drawings in detail, there is shown in FIG. 1 across-sectional view of a valve 10 in accordance with the presentinvention. The valve 10 of the preferred embodiment includes a flangednipple 12, an end washer 14, a flexible flow adjustment member 16,thermally reactive material 18, a shell 19, and a housing 20.

Referring now to FIGS. 2-4, the flanged nipple 12 is positioned adjacentto a first end of the flexible flow adjustment member 16, and ispreferably made of brass by methods, such as machining, well-known tothose skilled in the art. Alternatively, the flanged nipple 12 could bemade of bronze, copper, polymeric material, stainless steel or one of anumber of other materials well known to those skilled in the art tooffer structural strength, thermal stability, and resistance tocorrosion. The flanged nipple 12 has on a first end a flange 22 which issealingly engaged with a first end of the flexible flow adjustmentmember 16, as will be discussed more fully below. The outercircumferential edge 24 of the flange 22 is preferably circular and theedges of the outer circumferential surface 24 are preferably chamfered,for reasons which will become apparent when discussed below. The flangednipple 12 has a bore 26 centrally disposed therethrough which permitsthe passage of gasses, vapors, liquids, and mixtures of these throughthe flanged nipple 12 and into the flexible flow adjustment member 16.The size of the bore 26 can be varied depending upon the flow capacitydesired of the valve 10. Preferably, the bore 26 is approximately 0.156inches in diameter. When used as a “steam trap” within a steam systemgenerally including steam and condensate, a bore 26 of this size canaccommodate condensate flow rates of approximately 660 pounds per hourat 10 pounds per square inch, 1,485 pounds per hour at 50 pounds persquare inch, 2,099 pounds per hour at 100 pounds per square inch, and2,565 pounds per hour at 150 pounds per square inch (each based on waterat 60 degrees Fahrenheit). It will be obvious to those skilled in theart having read this disclosure that a larger diameter bore 26 wouldpermit greater flow rates and a smaller diameter would permit lesserflow rates.

A second end of the flanged nipple 12 opposite the flange 22 hasexternal threads 30 on its outer surface for attachment to the housing20, as described herein. In the preferred embodiment, the externalthreads 30 are American National Standard Taper pipe threads madepursuant to ANSI/ASME B1.20.1-1983, having a taper of one in sixteen or0.75 in/ft. Preferably the external threads 30 are 1/8-27 NPT male pipethreads, however, the pipe threads may be any size that will accommodatethe desired diameter of the bore 26 and that will accommodatepressure-tight attachment to the housing 20. Alternatively, the flangednipple 12 could have female threads (not shown) which would mate withmale threads (not shown) on the housing 20, or the union between theflanged nipple 12 and the housing 20 could be one of a number ofalternative configurations known to those skilled in the art such as acompression-type fitting, pressed fitting, or crimped fitting. Oppositethe flange 22, the bore 26 includes a hexagonal interior shape 28. Thishexagonal interior shape 28 is sized to fit a standard hex key or Allenwrench (not shown) used for applying torque to the flanged nipple 12 forassembly of the valve 10, which will be described fully below. Use of ahexagonal interior shape 28 and a hex key is the preferred method forinstallation of the flanged nipple 12 into the housing 20, however,other features that would facilitate installation of the flanged nipple12 into the housing 20 could be used. For instance, a slotted end on theflanged nipple 12 could be used without departing from the spirit andscope of the invention.

Spaced apart from the flange 22 at the opposite end of the flexible flowadjustment member 16 is a flat end washer 14 having an orifice 33therethrough. The end washer 14 is preferably made from brass, and madeby a machining process, but may be made from any material which will besubstantially dimensionally stable and rigid throughout the intendedtemperature range in which the valve 10 will be used, such as stainlesssteel and by any conventional process known to those skilled in the artfor making flat washers. The outer circumferential edge 32 of the endwasher 14 is preferably the same size and shape as the outercircumferential edge 22 of the flange 22. Those skilled in the art willrecognize upon reading this disclosure that the two outercircumferential edges 22, 32 need not be the same diameter but couldhave diameters different from one another if accommodation is made inthe flexible flow adjustment member 16 and shell 19, as will becomeapparent below. The edges of the outer circumferential edge 32 of theend washer 14 are preferably chamfered for reasons which will bediscussed below. The end washer 14 has an orifice 33 therethrough. Theorifice 33 is in fluid communication with the variable diameter passage37 and the bore 26. The orifice 33 preferably is the same size as thebore 26, but may alternatively be larger than the bore 26 withoutdeparting from the spirit and scope of the invention. It is desired,however, that the orifice 33 not be smaller than the diameter of thebore 26, otherwise the end washer 14 may undesirably restrict flowthrough the valve 10.

The flexible flow adjustment member 16 is essentially a flexible tubehaving a variable diameter passage 37 therethrough and an outer surface16 a. It is located essentially between the end washer 14 and the flange22 and preferably encompasses at least the outer circumferential edges24, 32 of the flange 22 and end washer 14, respectively, for reasonsthat will be discussed below with regard to assembly. In the preferredembodiment, the portion of the flexible flow adjustment member 16 whichencircles the outer circumferential edges 24, 32 of the flange 22 andend washer 14 respectively is at least 0.0625 inches thick to providesealing surfaces 34, 36 on the flange 22 and end washer 14,respectively. Those skilled in the art will recognize having read thisdisclosure that the thickness may be either more or less than 0.0625, solong as there is a sufficient thickness of material covering the outercircumferential edges 24, 32 to form a pressure-tight seal between theflexible flow adjustment member 16 and the shell 19, thereby creating asealed void 17 between the flexible flow adjustment member 16 and theshell 19, as discussed below. It is contemplated that the flexible flowadjustment member 16 need not be interposed between the shell 19 andouter circumferential edges 24, 32, and that the sealed void 17 may becreated by any method that would provide a sealed region between theshell 19 and flexible flow adjustment member 16 such as by sealing theflexible flow adjustment member 16 directly to the shell 19 without theuse of an end washer 14 or flanged nipple 12 (not shown).

The flexible flow adjustment member 16 must be selected to have thenecessary closure and opening capabilities through a range oftemperatures and provide a long life upon steady exposure to fluids,etc., at elevated temperatures. The flexible flow adjustment member 16is made of an elastomeric material, preferably VITON elastomericmaterial, and most preferably VITON GF300 manufactured by E.I. du Pontde Nemours & Co., Inc. located in Wilmington, Del., but may be made fromother resilient materials well known to those skilled in the art such asneoprene, butyl rubber, silicone, urethane rubber, EPDM, Hypalon,Viton-A, Viton-B, and Nordel elastomers. Hypalon, Viton-A, Viton-B andNordel are also manufactured by E.I. duPont de Nemours & Co., Inc.located in Wilmington, Del. In a preferred embodiment, the flexible flowadjustment member 16 is made by a process of molding, wherein theflanged nipple 12, end washer 14, and flexible flow adjustment member 16are assembled together as a unitary piece, as best shown in FIGS. 2 and3.

The variable diameter passage 37 passes longitudinally through theflexible flow adjustment member 16, thereby providing a constrictableflow path through the valve 10 in fluid communication with an interiorcavity 20 c of the housing 20 (discussed below), the orifice 33, and thebore 26, and when the valve 10 is used as a steam trap, the variablediameter passage 37 is, of course, in fluid communication with the steamsystem. The means of constricting the variable diameter passage 37 willbe described below. Preferably, the variable diameter passage 37 has adiameter equal to that of the bore 26 through the flanged nipple 12 tominimize turbulence through the valve 10. Those skilled in the art willrecognize upon reading this disclosure that the variable diameterpassage 37 may be larger than the diameter of the bore 26 if the bore 26alone is desired to control maximum flow rate through the valve 10, andmay be smaller than the diameter of the bore 26 if the variable diameterpassage 37 alone is desired to control maximum flow rate. In a preferredembodiment, wherein the valve 10 is to be used as a steam trap, thevariable diameter passage 37 is preferably 0.156 inches in diameter.However, those skilled in the art will recognize that the variablediameter passage 37 may be of any diameter that will permit apredetermined flow through the valve 10 and will permit the diameter tobe reduced to a point where flow through the valve 10 is terminated, asdescribed below. One substantial benefit of the nature of the materialand construction of the flexible flow adjustment member 16 is theability to seal off flow tightly even if contamination such as dirt ispresent in the variable diameter passage 37.

The outer surface 16a of the flexible flow adjustment member 16 ispreferably reduced in circumference at its longitudinal midpoint 35 tofacilitate compression (described more fully below) in that region ofthe flexible flow adjustment member 16, thereby facilitating thereduction in or termination of flow through the valve 10. The region ofreduced outer circumference also creates the inner boundaries of thesealed void 17 between the flexible flow adjustment member 16 and theshell 19 wherein the thermally reactive material 18 is encapsulated thuspositioning the thermally reactive material 18 in contact with the shell19 and the flexible flow adjustment member 16. It will be recognized bythose skilled in the art upon having read this disclosure that theflexible flow adjustment member 16 need not have a region of reducedouter circumference at its midpoint 35, but may have an outer diameterthat is equivalent across substantially the entire distance between theend washer 14 and the flange 22.

Reference is now made to FIG. 4. A shell 19 sealingly engages thesealing surfaces 34, 36 and in its unbent form (not shown) preferablyextends at least 0.0625 inches beyond each end of the flexible flowadjustment member 16. The shell 19 is essentially a short length oftube, and is preferably of round cross-section where, as discussedabove, the flange 22 and end washer 14 are made in a preferred circularshape. The shell 19 preferably has a slip fit over the flexible flowadjustment member 16 such that the shell may be slipped over theflexible flow adjustment member 16 from an end of the flexible flowadjustment member 16. The shell 19 is preferably made of brass, however,those skilled in the art having read this disclosure will recognize thatthe shell 19 could be made from any malleable metal which has highthermal conductivity, such as stainless steel. The malleability of thematerial is important due to the method of attaching the shell 19 to theflexible flow adjustment member 16, discussed below. High thermalconductivity is important because, in a thermally-reactive valve such asthe present invention, temperature changes must be rapidly detected andreacted to by the valve 10. It is also preferred that the shell 19 has ahigh degree of corrosion resistance. This may dictate differentmaterials depending upon the environment in which the valve 10 is used.The wall thickness of the shell 19 should be sufficient to resist theexpansive forces of the thermally reactive material 18 upon heating, ascompared to the flexible flow adjustment member 16. Preferably, the wallthickness of the shell 19 is 0.032 inches. The wall thickness of theshell 19 can be varied, thereby varying the thermal conductivity of theshell 19, to impart different temperature-reactive characteristics tothe valve 10, thicker wall thickness providing a slower response time,thinner wall thickness providing a more rapid response. This providesthe designer with the ability to custom design the response rate of thevalve 10 for different applications. The thermal reactivity of the valve10 can also be manipulated by employing different insulating orconductive coatings on the shell 19. Examples of such coatings areceramic or PTFE.

As best shown in FIGS. 1 and 4, the thermally reactive material 18,which expands in reaction to an increase in its temperature andcontracts in reaction to a decrease in its temperature, encircles theflexible flow adjustment member 16 in the sealed void 17 created betweenthe shell 19 and the outer surface of the flexible flow adjustmentmember 16. Thus, the thermally reactive material 18 is in contact withthe outer surface 16 a of the flexible flow adjustment member 16 forexecuting pressure thereon in response to a heating of the thermallyreactive material 18, thus causing the diameter of the variable diameterpassage 37 to decrease. Conversely, the thermally reactive material 18relieves pressure on the outer surface 16 a in response to a cooling ofthe thermally reactive material 18 to permit the diameter of thevariable diameter passage 37 to increase. While it is preferred that thevoid 17, and hence the thermally reactive material 18 encircle theflexible flow adjustment member 16, it is contemplated that the void 17need not completely encircle the flexible flow adjustment member 16, butneed only be in contact with a sufficient portion of the flexible flowadjustment member 16 to cause constriction and to permit expansion inresponse to changes in temperature and pressure of the steam system. Thehigher the coefficient of thermal expansion of the thermally reactivematerial 18 selected, the smaller the sealed void 17 need be. Thecomposition of the thermally reactive material 18 will be described morefully below in relation to the operation of the valve 10.

When the flexible flow adjustment member 16, thermally reactive material18, end washer 14, flanged nipple 12, and shell 19 are assembled asshown in FIG. 4, they form a modulator 40. The modulator 40 is mountedwithin the interior cavity 20 c (discussed below) and is, therefore, influid communication with the steam system. It should be understood thatthe shell 19 and variable diameter passage 37 are in fluid communicationwith the interior cavity 20 c and, when the valve 10 is used as a steamtrap, with the steam system. Referring now to FIG. 4, the modulator 40is assembled as follows. The flexible flow adjustment member 16 isinserted most of the way into the shell 19 such that only a smallportion of the void 17 is visible or accessible. The thermally reactivematerial 18, which is generally in a liquid state at the environmentalconditions of assembly, is injected into the void 17 whereupon theflexible flow adjustment member 16 is inserted the remainder of the wayinto the shell 19.

This assembly comprising the shell 19, flanged nipple 12, end washer 14,flexible flow adjustment member 16, and thermally reactive material 18is then placed in a compression tool 100 (shown in FIG. 5 and describedbelow) wherein the sleeve 19 is compressed or crimped onto the assembledflexible flow adjustment member 16, end washer 14 and flanged nipple 14such that the inner circumference of the shell 19 forms a pressure-tightseal with the sealing surfaces 34, 36 of the flexible flow adjustmentmember 16. It will now become apparent that the flange 22 and end washer14 provide a rigid backing, holding the flexible flow adjustment member16 in sealing engagement with the inner circumference of the shell 19.This sealing engagement is enhanced due to the shape of the compressedportion of the shell 19, having circumferential indentations 42, 44immediately inboard from the end washer 14 and flange 22, respectively,and rounded over ends 46, 48 immediately outboard from end washer 14 andflange 22, respectively. Those skilled in the art upon reading thisdisclosure will recognize that other methods of creating a pressuretight void 17 between the shell 19 and the flexible flow adjustmentmember 16 could be employed, such as through the use of a compressiontype fitting or threaded fitting. The modulator 40 is installed in theinterior cavity 20 c of the housing 20 such that the shell 19 is influid communication with the stream of fluid through the valve 10.

Referring now to FIG. 1, the housing 20 provides for attachment of thevalve 10 to tubing or piping (not shown) of the system into which valve10 is integrated. The housing 20 has a wall 20 d forming an interiorcavity 20 c, an inlet end 20 a and an outlet end 20 b. The interiorcavity 20 c is in fluid communication with the steam system. The housing20 is preferably generally tubular and has a hexagonal outer shape (notshown) to facilitate gripping the housing 20 with a wrench. It will berecognized by those skilled in the art upon reading this disclosure thatthe outer shape need not be hexagonal, but may be round and, in such acase, could be gripped by a pipe wrench or similar tool. The housing 20is preferably made from stainless steel, but those skilled in the artwill recognize that other materials, including bronze or polymericmaterials, offering high tensile strength and corrosion resistance thatwould be required in a coupling operating in a harsh environment wouldalso suffice.

Preferably, each end of the housing 20 has internal threads 50, 52 whichpermit attachment to tubing of the system into which the valve 10 isintegrated. The threads 50, 52 are preferably American National StandardTaper pipe thread (ANSI/ASME B1.20.1-1983) having a size of 1/2-14 NPT.Those skilled in the art upon reading this disclosure will recognizethat the threads 50, 52 could be either internal or external threads andcould be any size that would permit the level of flow for which thevalve 10 is rated. Additionally, it is contemplated that the housing 20could be attached to tubing of the system by any suitable type ofattachment mechanism, such as by welding, use of compression fittings,flanged connections, etc.

The housing 20 has in its interior cavity 20 c, a radially inwardlyextending throat 54 which is used as the point of attachment for thethreaded end of the flanged nipple 12. The throat 54 is preferablyunitary with the housing 20 and preferably has threads 56 whichcorrespond with the external threads 30 on the flanged nipple 12. Asstated above, those skilled in the art, upon reading this disclosurewill recognize that alternate means of attaching the flanged nipple 12to the housing 20 may be employed, such as by using a pressed orcompression type arrangement. The throat 54 is preferably located nearerone end of the housing 20 such that when the modulator 40 is installedinto the housing 20, the modulator 40 is positioned within the interiorcavity 20 c essentially equidistant from both ends of the housing 20.Those skilled in the art, upon reading this disclosure, will recognize,however, that the throat 54 need not be located to keep the modulator 40centrally disposed, but could be located such that the modulator isdisposed more toward one end of the housing 20 than the other withoutdeparting from the spirit and scope of the invention.

The valve 10 of the preferred embodiment is generally configured orassembled as follows. The modulator 40 is first assembled from itscomponent parts. As discussed above, the flange 22 of the flanged nipple12 is positioned adjacent to one end of the flexible flow adjustmentmember 16. A portion of the flexible flow adjustment member 16 encirclesthe outer circumferential edge 24 of the flange 22 and the outercircumferential edge 32 of the end washer. The flexible flow adjustmentmember 16 is partially inserted into the shell 19 such that only a smallportion of the void 17 is exposed. The thermally reactive material 18 isinserted into the void 17 whereupon the shell 19 is then slippedcompletely over the assembled components. The end washer 14 is thenpositioned adjacent to the end of the flexible flow adjustment member 16and the ends of the shell 19 are compressed (as described in detailbelow) such that the thermally reactive material 18 is sealed in thevoid 17 between the shell 19 and the flexible flow adjustment member 16.

Detailed assembly of the housing 20 and modulator 40 of the preferredembodiment is preferably accomplished as follows. The threads 30 of theflanged nipple 12 are threaded into the corresponding threads 56 in thethroat 54 of the housing 20 by inserting a hex key (not shown) into thehousing 20 through the second end 20 b of the housing such that itengages the hex portion 28 at the end of the bore 26 wherein the hex keyis then used to tighten the modulator 40 within the housing 20. A pipethread compound (not shown) or Teflon tape (not shown) is not used toseal the threaded joint between the modulator 40 and the throat 54because the threads are of the dry seal type. Alternatively, suchsealing features could be used if desired. It will be recognized fromthe foregoing description that the shell 19 will be in contact with aflow of fluid within the system to which the valve 10 is attached. Ifthat system is a steam system, the shell 19 will be in contact, i.e., influid communication, with the steam and/or condensate within the system.This is because the shell 19, and in fact, the modulator 40 are withinthe internal cavity 20 c. Likewise, the variable diameter passage 37will be in contact with the flow of fluid.

Referring now to FIGS. 1 and 4, when used as a steam valve, thepreferred embodiment of valve 10 operates as described herein. Atstartup of the steam system, because the interior cavity 20 c is exposedto cool temperatures, the thermally reactive material 18 is in arelatively unexpanded state and thus the pressure in the void 17 isrelatively low. As a result, the variable diameter passage 37 is open,thus permitting air, water, and non-compressibles to escape the steamsystem. As the steam system heats, the thermally reactive material 18,due to its physical characteristic of having a high degree of thermalexpansion, causes the pressure in the sealed void 17 between the shell19 and flexible flow adjustment member 16 to increase dramatically.Thus, the thermally reactive material 18 expands, causing the variablediameter passage 37 to narrow. When live steam reaches the interiorcavity 20 c and contacts the shell 19, the variable diameter passage 37closes, thus containing live steam within the steam system. As hot watercondensate (not shown) develops within the steam system, it passesthrough the inlet end 20 a of the housing 20 into the interior cavity 20c. The condensate at least partly fills the interior cavity 20 c andcontacts the shell 19, causing the thermally reactive material 18 tocool and, consequently, to rapidly contract, thereby permitting thevariable diameter passage 37 to open so that condensate can pass fromthe steam system.

Having described the general operation of the valve 10, it isappropriate to more fully describe the thermally reactive material 18.As stated above, the material used as the thermally reactive material 18must expand when subjected to a temperature increase and vice-versa and,therefore, must have a high coefficient of thermal expansion. Onecritical measure of performance when such valves 10 are used as steamtraps is their ability to retain live steam within the steam systemwhile simultaneously releasing condensate from the steam system at atemperature that closely parallels the saturated steam temperature. Ithas been found that in this respect the performance of the valve 10 isgreatly enhanced by configuring the thermally reactive material 18 suchthat at least a portion of the thermally reactive material 18 undergoesa phase change to vapor as temperature of the steam system increases. Inother words, when the valve 10 is used as a steam trap, at least aportion of the thermally reactive material 18 preferably is configuredto change phase to vapor in response to an increase in temperaturewithin the interior cavity 20 c (and within the steam system). Morepreferably, a substantial portion of the thermally reactive material 18is configured to change phase to vapor in response to an increase intemperature in the interior cavity 20 c.

To accomplish a change of phase of a substantial portion of thethermally reactive material 18 in accordance with the preferredembodiment, the thermally reactive material 18 is a mixture made fromabout fifty percent glycerin, forty-five and one-half percent isopropylalcohol, and four and one-half percent water (each by volume). It shouldbe understood that these volumetric percentages can vary considerably,so long as vaporization of at least a portion of the thermally reactivematerial 18 occurs during the transition from cooler to warmertemperatures. It is contemplated that other proportions of the abovestated ingredients could be employed, or a mixture of differentingredients could be employed, without departing from the scope andspirit of the invention. Indeed, by varying the relative quantities ofthe various ingredients that make up the thermally reactive material 18,the operating characteristics of the valve 10 can be custom tailored tothe particular needs within a system.

Materials that can be used individually or that can be combined toprovide the requisite phase change include water, alcohols includingmethanol, ethanol, propanol, butanol and the like, glycerin, alkyleneglycols, including ethylene glycol, propylene glycol, diethylene glycoland the like, and mixtures of the above and other chemical compounds.Additionally, fluorinated and chlorinated hydrocarbons commonly known inthe field as FREON compounds, a registered trademark of E.I. du Pont deNemours & Co., Inc., located in Wilmington, Del., and other compoundswell known to those skilled in the art as substitutes or environmentallybenign replacements for such FREON-type compounds may be used toaccomplish the preferred vaporization of the thermally reactive material18.

Configuring the valve 10 and particularly the thermally reactivematerial 18 such that at least a portion of the thermally reactivematerial 18 vaporizes, the flow of condensate is permitted to passthrough the variable diameter passage 37 at an average temperature thatgenerally parallels the average temperature of saturated steam withinthe steam system within a definable range. The definable range can bevaried, as described below, by varying the composition of the thermallyreactive material 18. Preferably the range is from zero to about 40percent. However, the definable range can be much larger, depending onthe desired function of the valve 10 within the steam system.Additionally, configuring the thermally reactive material 18 such thatat least a portion vaporizes, it is possible to control the degree ofoscillation of the temperature of condensate permitted to pass throughthe variable diameter passage 37. In the preferred embodiment, theaverage maximum temperature of condensate flow permitted to pass throughthe variable diameter passage 37 differs from the average minimumtemperature of condensate flow permitted to pass through the variablediameter passage 37 by up to about 25 degrees Fahrenheit. (See FIG. 15,discussed more fully before). It should be understood that by varyingthe mix of ingredients present in the thermally reactive material 18,the degree of oscillation may be reduced to at or about zero degreesFahrenheit. Accordingly, the valve 10 may be configured to closelymaintain a selected set of conditions within the steam system.Significantly, unlike prior art valves, the valve 10 of the presentinvention does not permit steam to flow through the variable diameterpassage once the steam system achieves the saturated steam temperature.

Referring now to FIG. 12, there is shown in block form a steam system200 used to test the ability of the valve 10 to control an outputtemperature of process water and the temperature of condensate passingthrough the variable diameter passage 37 of the valve 10. A thermal loadis applied to the steam system 200 by a steam-to-water heat exchanger202. The heat exchanger 202 is a shell-and-tube design with a surfacearea of 4.3 square feet, a flow capacity of 32 gallons per minute and isavailable as model number CL-30 from ITT Corporation, Upper SaddleRiver, N.J. 07458. Steam at saturation temperature and pressureconditions is supplied to the heat exchanger 202 via steam-in line 204.Process water is supplied to the heat exchanger 202 via a water-in line206 at sixty pounds per square inch (gauge). Water exits the heatexchanger 202 via a water-out line 208 and air, steam and/or condensateexit the heat exchanger 202 via a steam-out line 210. Steam into theheat exchanger 202 is controlled by a solenoid valve 212 and a steampressure regulator 214. Steam is supplied to the steam pressureregulator 214 at one hundred ninety pounds per square inch (gauge) andthe steam pressure regulator 214 was set to maintain approximately fiftypounds per square inch (gauge). The temperature of the saturated steamin the steam system is measured at a point TS approximately ten inchesbefore the heat exchanger 202. The valve 10 is located on the steam-outline 210 and the temperature of condensate flowing through the valve 10is measured at a point TC located approximately two inches before thevalve 10.

The tests were conducted with process water supplied to the heatexchanger 202 at ambient conditions (constant temperature ofapproximately 45-60° F.) and at a constant rate. The objective of thetests was to maintain a constant water-out temperature (TWO) of 180° F.To accomplish this, the water-out temperature TWO was monitored by acontroller (not shown) which actuated the solenoid valve 212 to initiateand terminate the flow of steam to the heat exchanger 202.

FIGS. 13 and 14 show the results of tests of prior art valves. FIG. 13shows the results of a one-half inch thermodynamic steam trap (notshown) of a type well known to those skilled in the art. Thethermodynamic steam trap was installed in place of the valve 10 in thesteam system 200. As can be seen, because of the backup and subsequentpurging of condensate within the steam system 200, the results obtainedwere not satisfactory. Although a constant TWO of 180 degrees Fahrenheitwas sought, the temperature varied from minimums of approximately135-160 degrees Fahrenheit to maximums of approximately 195-210. Thetemperature of condensate, TC, varied from minimums of approximately140-170 degrees Fahrenheit. FIG. 14 shows similar results for the sametest applied to a one-half inch bucket-type steam trap of the type wellknown to those skilled in the art. Again, although a constant TWO of 180degrees Fahrenheit was sought, the result was not achieved. TWO variedfrom minimums of approximately 125-160 degrees Fahrenheit and maximumsof approximately 200-210 degrees Fahrenheit. TC varied from minimums ofapproximately 160-170 degrees Fahrenheit to maximums of approximately180-210 degrees Fahrenheit. Clearly neither prior art valve demonstratessatisfactory ability to permit control of a process water temperature(TWO).

Referring now to FIG. 15, there is shown the test results for the valve10 of the preferred embodiment having a thermally reactive material 18made of a mixture containing fifty percent glycerin, forty-five andone-half percent isopropyl alcohol, and four and one-half percent water,each by volume. Again the objective of the test was to maintain aprocess water temperature (TWO) of 180 degrees Fahrenheit. TWO wasmaintained within maximum of between 183 and 190 degrees Fahrenheit andminimum temperature of between 165-175. TC was maintained between amaximum temperature of between 165-170 degrees Fahrenheit and a minimumtemperature of between 158-163 degrees Fahrenheit. The differencebetween averages of all minimum TC peaks and maximum TC peaks is roughly3-4 degrees Fahrenheit. As can be discerned from a comparison betweenthe prior art thermodynamic and bucket type valves and the valve 10 ofthe preferred embodiment, the valve 10 demonstrates a dramaticimprovement over the prior art valves in terms of regulating thetemperature (TC) of condensate permitted to pass through the variablediameter passage 37 and, accordingly, the output temperature of processwater (TWO). It will be recognized by those skilled in the art that awater-out temperature TWO which is substantially constant at the desiredtemperature demonstrates an efficiently-operating steam-to-water heatexchange. Efficiency in the exchange of heat between the steam andwater, particularly in a small heat exchanger 202 such as that employedin these tests, depends substantially on the efficient removal ofcondensate from the steam system 200, which is reflected by the nearconstant condensate-out temperature (TC). As is clearly demonstrated inFIG. 15, the valve 10 was extremely effective at removingefficiency-reducing condensate from the steam system 200 as evidenced bythe near constant water-out temperature TWO. The effectiveness of thevalve 10, and the fact that live steam was not expelled through thevalve 10, is further demonstrated in the proximity of the temperature ofcondensate TC expelled through the valve 10 and the water-outtemperature TWO.

As one skilled in the art will recognize having read this disclosure,and particularly as can be deduced from the test results shown in FIG.15, the valve 10 is quick acting and self-regulating, such that themodulator 40 begins to quickly and automatically pinch off or open thevariable diameter passage 37 as the thermally reactive material 18expands and vaporizes with the passage of hot materials and contractsand condenses with the passage of cooler materials. Accordingly, steamis not permitted to flow through the variable diameter passage once thesteam system achieves the saturated steam temperature.

The self-modulating action of the valve 10 also provides the benefit ofminimizing failure caused by contamination such as dirt or scale (notshown). If dirt or scale particles begin to plug the variable diameterpassage 37, the valve 10 will cool because of the reduced flow, thethermally reactive material 18 will contract, and the variable diameterpassage 37 will begin to open, allowing the contamination to pass. Thevariable diameter passage 37 will then adjust back to its originalmodulated size based on the load.

It will be recognized that the design of the valve 10 describedhereinabove provides the substantial benefit of greatly increased lifecompared with prior art designs. Responding automatically to condensatetemperatures, the valve 10 also greatly reduces the cost of installingand maintaining traps (not shown), eliminates down time in systems andproduct loss due to failed traps or valves of prior art designs, andgreatly increases energy efficiency by eliminating live steam loss. Thereaction time is less than that of prior art designs due to theimmersion of the shell 19 in the fluid medium reaching the valve 10. Theperformance of the valve 10 is greatly increased over prior art designsdue to the use of the thermally reactive material 18 disclosed herein,that changes phase in response to a change in temperature. When used asa steam trap, the increased efficiency and capacity of the valve 10 ofthe present invention, when compared with prior art designs, providessubstantial benefits when used in such applications as drip legs,winterizing steam tracing, process steam tracing, maintaining analyzersample lines, or when used in autoclaves, radiators, or for instrumentenclosure heater discharge. Alternatively, uses for the valve 10 of thepresent invention include, but by no means are limited to, temperaturecontrol, freeze protection, scald protection, etc. It is contemplatedthat the valve 10 may have application.

Referring now to FIGS. 5-7 and 11, as stated above, the shell 19 iscompressed onto the remainder of the modulator 40 through the use of acompression tool 100. The compression tool includes a base plate 164having a first end 164 a and an opposing second end 164 b, and asegmented cone 102 which sits atop the base plate 164 and within whichis disposed a modulator 40 for compression of its shell 19. A retainerplate 162 is disposed atop the base plate 164 and a receiver 124 isseated upon and fastened to the retainer plate 162 and is disposedradially outwardly from the segmented cone 102. An end plug 142 isattached to the second end 124 b of the receiver 124. Disposed adjacentto the end plug 142 and within the receiver 124 and adjacent to thesecond cylindrical portion 128 is a plunger 152 and first resilientmember 154. The first resilient member 154 contacts the end plug 142 atone end and at its opposite end contacts the plunger 152. The plunger152 contacts the first resilient member 154 at its upper end and thesecond end 102 a of the segmented cone 102 at its lower end. A secondresilient member 123 is disposed within a longitudinal bore 112 of thesegmented cone 102 and elastic members 125 are disposed within thesegmented cone 102 as further described below.

Referring now to FIGS. 5-7, the segmented cone 102 has a first end 102 aand an opposed second end 102 b and consists of eight longitudinalsegments 104 a through 104 h. The individual segments 104 a through 104h are preferably made by making radial cuts 105 through a unitarysegmented cone (not shown) such that each segment 104 a through 104 hhas two longitudinal faces 103 and the longitudinal face 103 of onelongitudinal segment 104 a through 104 h is adjacent to the longitudinalface 103 of the adjacent longitudinal segment 104 a through 104 h. Adescription of the method of making the cuts is omitted for purposes ofbrevity as such methods are well known to those skilled in the art.Preferably the cuts through the unitary segmented cone are 0.025 incheswide. Those skilled in the art will recognize upon reading thisdisclosure that the cuts need not be 0.025 inches wide, but may be anywidth that permits the segmented cone 102 to compress the shell 19 yetremain relatively easily retractable, once compression of the shell 19is complete. The segmented cone 102 is preferably made of ahigh-strength light-weight material, such as AH-5 tool steel having ahardness of Rc 55-58.

Referring now to FIG. 7, the outer shape of the segmented cone 102consists of a second frusto-conical surface 106 adjacent to the secondend 102 b of the segmented cone 102, a first frusto-conical surface 108adjacent to the first end 102 a of the segmented cone 102, and acylindrical surface 110 disposed therebetween. The second frusto-conicalsurface 106 and first frusto-conical surface 108 have angles ofinclination A, B of 20 degrees. Those skilled in the art upon readingthis disclosure will recognize that the angle of inclination A, B of thesecond and first frusto-conical surfaces 106, 108 should be identical ornearly identical to provide uniform compression along the length of theshell 19 (as will be discussed below) but may be other than twentydegrees without departing from the spirit and scope of the invention. Alongitudinal bore 112 passes longitudinally through the center of thesegmented cone 102. At the end of the longitudinal bore 112,corresponding with the second frusto-conical surface 106, is an internalthroat 114, the function of which will become apparent below. At theopposite end of the longitudinal bore 112 is the forming section 116,which imparts the final formed shape to the shell 19 in the processdescribed below. The forming section 116 includes two circumferentialchannels 118 and two circumferential ridges 120, the combination ofwhich form the circumferential indentations 42, 44 (best shown in FIG.4) and rounded over ends 46, 48 on the shell 19.

Each segment 104 a through 104 h of a preferred embodiment of thesegmented cone 102 has a cavity 122 in each longitudinal face 103 whichcorresponds with and opposes a cavity 122 on the adjacent, opposinglongitudinal face 103. Preferably, the cavities 122 are flat bottomed.Disposed within each opposing pair of cavities 122 in adjacentlongitudinal faces 103 of segments 104 a through 104 h are the elasticmembers 125, which assist in maintaining proper spacing of the segments104 a through 104 h during assembly of the compression tool 100 andsubsequent compression of the shell 19. Consistent spacing of thesegments 104 a through 104 h assists in distributing the compressiveload on the shell 19 evenly around the circumference of the shell 19.The elastic members 125 provide the additional benefit of assisting inseparating the segments 104 a through 104 h following compression of theshell 19. The elastic members 125 are generally cylindrically shaped andare made of elastomeric material which preferably is rubber. Thoseskilled in the art will recognize upon reading this disclosure thatother means could be used to properly space and separate the segments104 a-104 h, such as configuring resilient retainer plates (not shown)to fit between corresponding faces of each segment 104 a-104 h, orsprings could be used, without departing from the spirit and scope ofthe invention.

Referring to FIGS. 5-7, the second resilient member 123 is disposedwithin the longitudinal bore 112 to assist in radially expanding thesegments 104 a through 104 h following compression of a shell 19 to forma modulator 40. The second resilient member 123 is retained within achamber 115 bounded within the segmented cone 102 by the internal throat114 at the top of the chamber 115 and by the forming section 116 at thebottom of the chamber 115. The second resilient member 123 is preferablymade from an elastomeric material such as urethane rubber and ispreferably formed in the shape of a solid cylinder. Those skilled in theart will recognize that the second resilient member 123 may be made inany shape that would permit placement within the longitudinal bore 112and may be made from any resilient material. Alternative structures forseparating the segments 104 a through 104 h following compression of theshell 19 are spheres or they could be egg shaped.

Referring now to FIGS. 5 and 8, the compression tool 100 also includes areceiver 124 for receiving the segmented cone 102 during use of thecompression tool 100. The receiver 124 is preferably made of ahigh-strength, light weight material, such as steel. Those skilled inthe art will recognize upon reading this disclosure that the receiver124 could be made from any material having sufficient hardness andtensile strength to force the segments 104 a through 104 h together asthe receiver 124 is forced over the segments 104 a through 104 h. Asbest shown in FIG. 8, the receiver 124 has a first end 124 a, anopposing second end 124 b, and an internal passage 126 passinglongitudinally through the receiver 124. The internal passage 126includes a first conical portion 130 adjacent to the first end 124 a, afirst cylindrical portion 132 adjacent to the first conical portion 130,a second conical portion 128 adjacent to the first cylindrical portion132, and a second cylindrical portion 139 adjacent to the second conicalportion 128 and the second end 124 b. At the outboard end of the secondcylindrical region 139 is a set of internal threads 140 for attachmentof the end plug 142, as discussed below. The internal threads 140 arepreferably straight machine screw threads, however, threads of virtuallyany nature could be employed without departing from the spirit and scopeof the invention. The receiver 124 also has a circumferential groove 138at its end opposite from the threads 140. The function of thecircumferential groove 138 is described below.

Referring to FIGS. 5, 8, and 9, an end plug 142 is attached to the endof the receiver 124. The end plug 142 is preferably made of steel. Theend plug 142 has external threads 144 which mate with internal threads140 in the internal passage 126 of the receiver 124 and which arepreferably straight machine screw threads. The end plug 142 could befixed to the receiver 124 by alternative means such as by welding. Theend plug 142 also includes a shoulder 146 which permits the end plug 142to be securely tightened to the receiver 124 since straight machinethreads rather than tapered threads are used. To assist in assembly, theouter surface 148 of the shoulder 146 preferably has a hexagonal shapefor engagement with a wrench (not shown). Alternatively, the end plug142 could have a recess (not shown) in the exposed, upper end 150 havingan internal hexagonal shape to receive a hex key (not shown).

Referring to FIGS. 5 and 10, there is shown the plunger 152 and thefirst resilient member 154. Referring to FIG. 10, the plunger 152 has acontact surface 156 which contacts the second end 102 b of the segmentedcone 102. The plunger 152 includes a shoulder 158 around its lowercircumference which is sized to slide freely within the secondcylindrical portion 139 of the receiver 124. The plunger 152 alsoincludes a hub 160 which extends upwardly from the shoulder 158. Thefirst resilient member 154 is disposed over the hub 160 and is, at oneend, in engagement with the shoulder 158. The end of the first resilientmember 154 opposite the shoulder 158 is in contact with the end plug 142to assist in disassembly as will be discussed below. Referring to FIGS.5 and 11, there is shown the retainer plate 162 and base plate 164. Asbest shown in FIG. 11, the retainer plate 162 has a first end 162 a andan opposing second end 162 b, and ridge 166 extending upwardly from thesecond end 162 b which mates with the circumferential groove 138 on theend of the receiver 124 and which ridge 166 and groove 138 cooperate tomaintain the retainer plate 162 centrally disposed with respect to thereceiver 124. The retainer plate 162 is fixedly attached to the receiver124, preferably by bolts or screws (not shown) passing through theretainer plate 162 and into the bottom end of the receiver 124. The baseplate 164 has a first end 164 a and an opposing second end 164 b.

Alternatively, the retainer plate 162 can be attached to the receiver124 through mating threads (not shown) on the radially outer surface ofthe circumferential groove 138 and the radially inner surface of theridge 166. The retainer plate 162 includes a throughbore 168 having aninner diameter which is sized to slidably engage the outer cylindricalsurface 170 of a central hub 172 extending upwardly from the base plate164. Also extending upwardly from the second end 164 b of the base plate164 is a circumferential, annular hub 176 which, during operation, seatsagainst the end surface 174 of the retainer plate 162 as describedbelow. The base plate 164 is also provided with a mounting hole 178therethrough having at its lower end internal threads 180 which areadapted for retaining a modulator 40. A set screw 181 is disposed withinthe portion of the mounting hole 178 nearer the first end of the baseplate 164 and has external threads (not shown) which mate with internalthreads 180. Disposed within the end of the mounting hole 178 nearer thesecond end of the base plate 164 are internal threads 182 that engagethe external threads 30 of the flanged nipple 12 to secure the modulator40 into the compression tool 100 during assembly. The retainer plate 162and base plate 164 are made from high-strength, light-weight materialwhich is dimensionally stable under repeated high compressive loading.The retainer plate 162 and base plate 164 are preferably made of steel.Those skilled in the art will recognize upon reading this disclosurethat the retainer plate 162 and base plate 164 may be made from anynumber of different materials so long as the dimensional stabilityrequirements described above are met.

In operation, the compression tool 100 is assembled and used as follows.Referring to FIGS. 5 through 11, a modulator 40 is joined to the baseplate 164 by screwing the external threads 30 on the modulator 40 intothe internal threads 182 of the base plate 164. The modulator 40 isscrewed into the base plate 164 until the end of the flanged nipple 12contacts the set screw 181, which is set at a predetermined depth withinthe mounting hole 178 to achieve consistency in the depth of engagementof the modulator 40. The shell 19, which is in its uncompressed state(not shown), is positioned on the flexible flow adjustment member 16using a spacing fork (not shown) which is inserted beneath the shell 19thereby creating a space of predetermined thickness between the shell 19and the central hub 172. The thickness of the spacing fork ispredetermined to work in conjunction with the positioning of the setscrew 181 within the mounting hole 178 to locate the shell 19symmetrically with respect to the end washer 14 and flange 22, in otherwords, to locate the shell 19 so that an equal amount of the shell 19extends beyond the end washer 14 and the flange 22. The spacing forkremains in place until the shell 19 is properly positioned and then thespacing fork is removed. The shell 19 maintains its vertical positiondue to friction between it and the sealing surfaces 34, 36. It isunderstood by those skilled in the art that instead of the spacing fork,a spring-loaded floater (not shown) could be used to maintain the properalignment of the shell 19.

To assemble the compression tool 100, the end plug 142 is threaded ontothe upper end of the receiver 124, the first resilient member 154 isplaced over the hub 160 of the plunger 152, and the first resilientmember 154 and plunger 152 are inserted into the second cylindricalportion 139 of the receiver 124 such that the first resilient member 154is in contact with the end plug 142. The segmented cone 102, in itsassembled state having the second resilient member 123 and elasticmembers 125 installed therein, is placed within the receiver 124, andthe retainer plate 162 is attached to the bottom end of the receiver124. This entire assembly is then set down over the modulator 40 andbase plate 164 such that the modulator 40 is received within the formingsection 116 and the top surface of the central hub 172 contacts thebottom surface of the segmented cone 102.

A compressive force from an external source (not shown) is exertedagainst the end plug 124 or, alternatively, against an upper surface ofthe receiver 124 such that the receiver 124 moves downwardly withrespect to the segmented cone 102. As the receiver 124 travelsdownwardly with respect to the segmented cone 102, the second conicalportion 128 of the receiver 124 corresponds with the smallerfrusto-conical portion 106 of the segmented cone 102, the first conicalportion 130 of the receiver 124 corresponds with the firstfrusto-conical surface 108 of the segmented cone 102, and the firstcylindrical portion 132 of the receiver 124 corresponds with thecylindrical portion 110 of the segmented cone 102. The correspondence ofthese features causes the segments 104 a through 104 h to draw radiallyinwardly as the receiver 124 travels downwardly with respect to thesegmented cone 102, thereby compressing the shell 19 within the formingsection 116. The downward movement of the receiver 124 also causes thesecond end 102 b of the segmented cone 102 to force the plunger 152upwardly causing compression of the resilient member 154. Downwardmovement of the receiver 124, by causing radially inward movement of thesegments 104 a through 104 h and thus decreasing the diameter of thelongitudinal bore 112, also causes the second resilient member 123 andelastic members 125 to become compressed. The useful function of thiscompression will become apparent below.

Force is applied until the circumferential hub 176 of the base plate 164contacts the bottom surface of the retainer plate 162, whereuponcompression of the shell 19 is complete. As best shown in FIGS. 5 and11, the downward travel of the receiver 124, and, correspondingly, thedegree of compression of the shell 19, can be easily adjusted by varyingthe thickness of the circumferential hub 176. Having completed thecompression of the shell 19 to form a modulator 40, the compression tool100 is retracted to remove the modulator 40. In this regard, theexternal source of compressive force is removed whereupon the compressedfirst resilient member 154, second resilient member 123, and elasticmembers 125 act to assist in retraction of the compression tool 100. Thefirst resilient member 154 exerts force against the end plug 142 andagainst the second end 102 b of the segmented cone 102 such that thereceiver 124 is thrust upwardly with respect to the segmented cone 102,thereby permitting the second resilient member 123 and elastic members125 to thrust the segments 104 a through 104 h radially outwardly suchthat the modulator 40 may be removed.

It will be appreciated by those skilled in the art that changes could bemade to the embodiment described above without departing from the broadinventive concept thereof. It is understood, therefore, that thisinvention is not limited to the particular embodiment disclosed, but itis intended to cover modifications within the spirit and scope of thepresent invention as defined by the appended claims.

What is claimed is:
 1. A valve for automatically modulating a flow offluid, the valve comprising: a flexible flow adjustment member having avariable diameter passage therethrough and an outer surface, wherein theflexible flow adjustment member is made from VITON; a shell surroundingat least a portion of the outer surface and creating a void between theshell and the outer surface, the shell being in contact with the flow offluid; and a thermally reactive material that expands when heated andcontracts when cooled, the thermally reactive material being within thevoid and in contact with the outer surface of the flexible flowadjustment member for exerting pressure thereon in response to a heatingof the thermally reactive material to cause a diameter of the variablediameter passage to decrease and to relieve pressure thereon in responseto a cooling of the thermally reactive material to permit the diameterof the variable diameter passage to increase, a substantial portion ofthe thermally reactive material being configured to change phase tovapor in response to an increase in temperature within the internalcavity.
 2. A valve for automatically modulating a flow of fluid, thevalve comprising: a flexible flow adjustment member having a variablediameter passage therethrough and an outer surface, wherein the flexibleflow adjustment member is made from VITON GF300; a shell surrounding atleast a portion of the outer surface and creating a void between theshell and the outer surface, the shell being in contact with the flow offluid; and a thermally reactive material that expands when heated andcontracts when cooled, the thermally reactive material being within thevoid and in contact with the outer surface of the flexible flowadjustment member for exerting pressure thereon in response to a heatingof the thermally reactive material to cause a diameter of the variablediameter passage to decrease and to relieve pressure thereon in responseto a cooling of the thermally reactive material to permit the diameterof the variable diameter passage to increase, a substantial portion ofthe thermally reactive material being configured to change phase tovapor in response to an increase in temperature within the internalcavity.
 3. A valve comprising: a housing having a wall defining aninterior cavity; a modulator mounted within the interior cavity, themodulator including: a shell in fluid communication with the interiorcavity; a flexible flow adjustment member within the shell, the flexibleflow adjustment member having a variable diameter passage therethrough,the variable diameter passage being in fluid communication with theinterior cavity, wherein the flexible flow adjustment member is madefrom VITON; a void between the flexible flow adjustment member and theshell; and a thermally reactive material within the void and in contactwith the shell for thermal communication therebetween, at least aportion of the thermally reactive material being configured to changephase to vapor in response to an increase in temperature within theinterior cavity.
 4. A valve comprising: a housing having a wall definingan interior cavity; a modulator mounted within the interior cavity, themodulator including: a shell in fluid communication with the interiorcavity; a flexible flow adjustment member within the shell, the flexibleflow adjustment member having a variable diameter passage therethrough,the variable diameter passage being in fluid communication with theinterior cavity, wherein the flexible flow adjustment member is madefrom VITON GF300; a void between the flexible flow adjustment member andthe shell; and a thermally reactive material within the void and incontact with the shell for thermal communication therebetween, at leasta portion of the thermally reactive material being configured to changephase to vapor in response to an increase in temperature within theinterior cavity.
 5. A valve comprising: a housing having a wall definingan interior cavity; a modulator mounted within the interior cavity, themodulator including: a shell in fluid communication with the interiorcavity; a flexible flow adjustment member within the shell, the flexibleflow adjustment member having a variable diameter passage therethrough,the variable diameter passage being in fluid communication with theinterior cavity; a void between the flexible flow adjustment member andthe shell; and a thermally reactive material within the void and incontact with the shell for thermal communication therebetween, at leasta portion of the thermally reactive material being configured to changephase to vapor in response to an increase in temperature within theinterior cavity; the housing further including a radially inwardlyextending throat, the modulator being mounted to the throat.
 6. Thevalve of claim 5, further comprising: an end washer having an orificetherethrough and an outer circumferential edge, the end washerpositioned at a second end of the flexible flow adjustment member, theorifice being in fluid communication with the variable diameter passage,the outer circumferential edge of the washer being sealingly engaged tothe flexible flow adjustment member; and a flanged nipple having a boretherethrough and a flange at a first end of the nipple, the flange beingsealingly engaged with a first end of the flexible flow adjustmentmember, the bore being in fluid communication with the variable diameterpassage, and a second end of the flanged nipple being connected to thethroat.